82 HABITS 



Of this genus three species are common. 



Pycnosouia inarginale Wied. is a " thick-set, stoutly built fly, 

 about 9 to 13 millimetres in length, with an average wing 

 expanse of 22^ millimetres, with orange-buff-coloured face 

 and shining, metallic plum-purple and metallic green body, 

 recognisable at once by the dark brown front border to the 

 wings. (Pi. XVII, fig. I.) 



" Eyes in male meeting together in the middle line above, in 

 female separated by a cadmium-orange-coloured space (the front), 

 practically equal to one-third of the head in width ; male with 

 an area on the upper half of each eye consisting of larger facets 

 than the remainder; antenncB orange, the arista and hairs clothing 

 it brown ; ground colour of tJiorax and abdomen varying as 

 indicated above; thorax with a shimmering, pollinose, transverse 

 band of pearl-grey on its anterior and posterior third, making 

 these areas duller than the remainder which appears in certain 

 lights as a brown transverse band ; abdomen with a shimmering, 

 pollinose band on the basal portion of the second segment, and 

 similar lateral patches on the third and fourth segments ; first 

 segment and hind borders of second and third segments usually 

 darker than remainder of abdomen ; ivings hyaline, with a dark 

 brown patch at the base, which is continued as a stripe along the 

 fore border to the end of the second vein ; legs metallic purplish- 

 brown or black." 



This species "has a very wide distribution in Africa and even 

 ranges eastwards as far as Quetta" (Austen, 1904, p. 664). 



Pycnosoma chloropyga Wied. is a smaller species, from 6\ to 

 10 millimetres in length, with an average wing expanse of 

 18 millimetres. "Metallic bluish-green, or metallic plum-purple, 

 last two segments of abdomen brassy-green; wings hyaline, with 

 a dark blotch near the base. (PL XVII, fig. 2.) 



" Head in the male with the eyes almost meeting in the middle 

 line above, in the female with eyes widely separated ; lower part 

 of head, including anterior portion of orbital margins, )-ellowish- 

 grey, clothed with short silvery white hair ; upper part of front 

 in female shining purplish-black ; antennec black, arista and 

 hair clothing it brown. Thorax marked as shown in PI. XVII, 

 fig. 2, the dark areas deep black, the lighter portions metallic 



